In a work performed in a clean atmosphere such as a work at a manufacturing stage of semiconductors or electronic components or in a work at a manufacturing stage of pharmaceutical products, the works are performed in a clean work environment in which an inside is kept in a dust-free/sterile state so that contaminants do not enter from an external environment. As such clean environment, clean rooms are generally used. In this clean room, a worker wearing a dust-free clothes performs a work. However, in order to improve dust-free guarantee standards and sterile guarantee standards, a work is performed by constructing a more highly clean zone in the clean room.
As a method of constructing a highly clean zone, RABS (restricted-access barrier system) is used. In the RABS, a zone surrounded by wall surfaces with a lower part open is provided in a part of the clean room, and a laminar flow (hereinafter referred to as a “laminar flow”) of clean air in unidirectional air flow flowing from an upper side to a lower side is made to flow therein and strict access restriction is set for workers. In this RABS, a worker performs a work inside through a glove or half-suit provided on the wall surface. Moreover, as another method constituting the highly clean zone, an isolator device is used. With this isolator device, a chamber sealed from an external environment is used, and a worker performs a work from an outside of this chamber through the glove or half-suit.
Inside the RABS or isolator device, the laminar flow flows to the lower side from a clean air supply device provided on the upper side through an HEPA filter or the like. With the RABS or isolator device, since a worker does not enter therein in order to perform a work, a clean zone in a highly dust-free/sterile state can be ensured. However, even if this clean zone guarantees Grade A (Guidance on the Manufacture of Sterile Pharmaceutical Products by Ministry of Health, Labour and Welfare) required for the manufacture of pharmaceutical products, it is likely that particles each having a grain size of 0.5 μm or more (hereinafter, referred to as a “particle”) are contained up to 3520 particles/m3 as an upper limit. These particles descend from the upper side to the lower side though the clean zone on the stream of the laminar flow. Moreover, these particles also contain floating bacteria in the air.
In such clean zone, a filling work of pharmaceutical products or the like is performed, for example. In the filling work of the pharmaceutical products, containers such as vials whose outer surfaces and insides are sterilized are conveyed to a filling machine while traveling along a conveyer or a guider. Then, the container filled with the pharmaceutical products is sealed, whereby sterile filling is completed. At this time, the container before filling is traveling toward the filing machine through the clean zone with its opening portion (filling port) directed upward, and it is likely that the extremely small quantity of particles (including floating bacteria) descending on the stream of the laminar flow are mixed into the container before filling.
As a method against this, further upgrading of the dust-free/sterile state in the clean zone can be considered. However, it is actually difficult to perform a filling work of pharmaceutical products by further upgrading the dust-free/sterile state of the inside of the RABS or isolator device.
Thus, various measures have been taken in the sterile filling device for excluding the extremely small quantity of particles in these clean zones as much as possible. In a sterile filling method proposed in Patent Literature 1 described below, for example, a container whose inside is sealed and sterilized in advance is used. This container is connected to a specific filling device, and the pharmaceutical products are filled therein by inserting a nozzle into the container. Subsequently, the container is sealed still in the state where the pharmaceutical product in the container is not exposed to the outside air.